The present invention relates to a method for manufacturing an integral multilayer foam board with concave/convex surface and multiple colors. The multilayer foam board is molded with multiple convex portions defined by concave frame lines. By means of partially planing the convex portion of the foam body and re-heating the planed foam board, the convex portions thereof form concave portions, while the frame lines reversely become convex. The multilayer foam board has an appearance with multiple layers of colors and has a concave/convex surface which provides slipproof effect and massaging function for a user's sole.
Conventionally, a multilayer foam board is made by a mold. The mold can be designed with irregular or otherwise geometrical shape, whereby after the foaming material is fed into the mold and foamed, the foam board is formed with a geometrical figure to improve the appearance thereof. In addition, after the foam board is molded, a color can be added to the foam board to beautify the product. However, some shortcomings exist in the conventional measure as follows:
1. The mold has an irregular concave/convex shape so that the foam board is molded to have corresponding irregular concave/convex shape. This creates a better appearance and a slipproof effect of the foam board. However, the face of the foam board has a single color and is monotonous. With respect to a multilayer foam board with multiple colors in the respective layers, the face of the board still only has a single color and fails to create a satisfactory appearance.
2. After the foam board is molded, an outer face plate printed with colorful decorative pictures can be attached to the face of the foam board to improve the appearance thereof. Such outer face plate is adhered to the face of the foam board by an adhesive agent and is apt to separate from the face of the foam board after a period of use. In addition, in the case that the foam board is used to manufacture a shoe sole, a wearer's sole always abrades off the printed pictures of the face plate. In the case that the foam board is used to manufacture other articles such as a paving, the printed pictures of the face plate are also subject to abrasion and apt to detach from the face plate after a short period of use. Moreover, the face plate is additionally manufactured, printed and adhered to the foam board, so that the manufacturing cost of the foam board product is relatively high.
3. The concave/convex surface of the foam board is able to massage a user's sole. However, generally the foam board is additionally processed to form the concave/convex surface after the foam board is molded. This is not economic.